☰
GET A QUOTE

Q: Jerking when accelerating (after slowing down).

asked by on October 24, 2016

Hi mates, I am just wondering if you can help me out with the jerking issue on my 2007 Foresters. When I accelerate from a complete stop, there's nothing wrong, no matter how hard I hit the accelerator. However whenever I slow down to around 16-17mph and then accelerate, there will be a short moment of hesitation before it jerks (it sounds like the car got confused, doesn't know which gear to shift and then decides to down shift too quickly, making a big shock/jerk). Some mechanic told me that could be the transmission, others said the engine that acting up which make me more confused. Do you have any suggestion on which to look at? I know a bit about some technical so hopefully can understand your advanced analysis. Thank you for your help. Cheers, Hugh

My car has 110000 miles.
My car has an automatic transmission.

Recommended Services

Throttle Body Replacement $267.08 - $1836.29 Get a Quote
Car is hesitating and bucking Inspection $94.99 - $114.99 Get a Quote
Or For Any Other Auto Repairs Get a Quote

Hi there. From my experience with this vehicle the issue is almost always a failure in the throttle body. It is very common for the throttle body to have an intermittent failure and for it to run like this. Most of the time it is because of a flat spot in the throttle body motor which causes this strange hesitation that you have.

I typically test the throttle body with a scan tool to monitor the sensors on the throttle body as will as from the accelerator pedal sensors. There were also issues with this throttle body which causes it to eventually fail completely. It can also be caused by a dirty fuel injector or carbon build up in the engine but that is not as common.

If you’d like to have this repaired, consider YourMechanic, as one of our mobile technicians can come to your home or office to diagnose your jerking symptoms and help you make the necessary repairs.

Subaru
Sensors
Throttles
Forester
2007
acceleration
hesitation
H4-2.5L
jerking
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I properly secure a LATCH compatible car seat into my seats?
If you are using a LATCH (Lower Anchors and Tethers for Children) compatible car seat, you are already off to a good start as the LATCH system uses a standard set of attachments and tethers to consistently install car seats...
Read more
Gear shift lever stuck in Park
This is a very common problem for your type of vehicle. Oftentimes, there is a component in the shifter mechanism that fails, and causes the shifter to be unable to come out of park. The repair for this is to...
Read more
Whining noise and dripping fluid under the drivers side
If the whining noise happens in park or neutral, I would check your power steering fluid (https://www.yourmechanic.com/services/power-steering-fluid-service). The power steering pump makes a whining noise when it is low on fluid. You will need to find the source of the...
Read more
White smoke from exhaust while idling when pedal is pressed. Vehicle is a 2008 BMW 750i
The white smoke is usually a sign that you may have a blown head gasket which is also accompanied by the car overheating. The engine is also most likely burning the oil which is why it is consuming it but...
Read more
My car will not rev passed 3 rpm not sure what the problem is engin and tranny are good need help
The engine may have a bad distributor causing low power. If you have replaced the fuel filter and still get poor acceleration then check the fuel pressure and if it is normal then remove distributor cap and check for oil...
Read more
Parking brake is locked up.
The car can still be towed. Often, the metal wires cables that control the mechanical parking brake may rust in their insulation and that causes the cable to bind and seize. These systems can fail in both the released position...
Read more
Is it dangerous to drive while advancetrac warning light is on?
As you may know, the Advancetrac warning light relates to your vehicle's traction control system. The traction control system monitors the steering stability of the vehicle and engages when loss of traction has been detected. This is done by the...
Read more
Electrical problem in Nissan pathfinder 01, burning out my spark plugs and temp censor in the last two months.
The only way you can burn out spark plugs in a month is to have your engine running so lean it will have misfires, low power and other driveability problems. I suggest having fuel system pressure tested and computer tested...
Read more
Rough idling, no power on acceleration, revs by itself, shuts off
The first thing I check for in any drivability problem is air leaks. Any air that gets into the engine without going through proper channels will lean out the system and cause these kinds of problems. Look under the hood...
Read more

Related articles

How Long Do Wiring Harnesses Last?
Car wiring harnesses connect all the different electrical systems and components in a vehicle. Wiring harnesses can last the lifetime of the vehicle.
Read more
2012 Volkswagen Jetta vs. 2012 Subaru Forester: Which One Should I Buy?
Mid-size sedans are the realm of small families or commuters who want a slightly larger vehicle than a subcompact or compact car, yet don’t want to fully give up their good gas mileage. The sedan offers more comfort and space...
Read more
The Best Used Cars to Buy If You Live in a Cold Climate
If If you live in a cold climate, likely one of your biggest concerns when you are considering which used vehicle you should buy is how well it will perform in snowy, icy conditions. We have evaluated a number of...
Read more

Browse other content

Estimates
Cities
Maintenance
Cars